Telephone-transmitter.



' PATENTED FEBJO, 1903.

P. s; TUCKER. TELEPHONE TRANSMITTER. Arr nmulon FILED JULY 6, 1902.

NORR'S 957255 00., mom-Una, wumumoy. u. c.

UNITED STATES PATENT OFFICE.

FRANK S. TUCKER, OF'BOSTON, MASSACHUSETTS, ASSIGNOR TO ELECTRIC GAS LIGHTING COMPANY, OF BOSTON, MASSACHUSETTS.

TELEPHONE-TRANSMITTER.

SPECIFICATION forming part of Letters Patent No. 720,085, dated February 10, 1903.

Application filed July 5,1902. Serial No. 114,360. (No model.)

To all whom it may concern:

Be it known that I, FRANK S. TUCKER, of Boston, Massachusetts, have invented a new and useful Improvement in Telephone-Transmitters, of which the following is a specification.

My invention relates to the combination of the receptacle for the carbon granules, the back strap or bridge, the diaphragm, and

[0 means of retaining the diaphragm.

My invention consists in certain novelties of structure in, as well as a novel combination of, the parts.

My invention will be plain from the accompanying drawings, in which- Figure 1 is a plan View. Fig. 2 is a vertical section on the line 2 2 of Fig. 1, and Figs. 3 and 4 are details of modified forms. Fig. 5 is a section showing certain modifications.

In the drawings, A is an ordinary form of the mouthpiece, and B the casing, which is constructed with a raised part or rim 1), on the interior (or, if desired, on the exterior) of which rim is a grooqe C to receive the ends of the bridge, the rim-itself being slotted or partly broken away therefor at a down to the groove. If the groove is exterior, the ends of the bridge must of course be constructed to turn over the exterior of the part or rim 1), 0 as shown in Fig. 5. Within casing B rests diaphragm E.

D is a back strap or bridge, its ends 01 d being formed into tongues adapted to slide in the groove C, (this groove being shown as in terior,) to which one tongue is admitted by the slot at c.

F F are two curving springs, preferably pivoted to the bridge at f at their centers and may have their extremities slightly turned 0 over to bear upon the diaphragm E. This construction will be plain from Figs. 1 and 2.

It will be seen that when the one tongue of the bridge D is admitted to the groove C and the other tongue by slot 0 the turned-up ends 5 of the springs F F will bear against the diaphragm, while the bridge can be moved into any position desired upon the same. The advantage of the springs F F, pivoted to the bridge, is that a constant spring-pressure will better hold the diaphragm. In place of the springs F F one spring of proper shape may be used, as shown in Fig. 3, or in place of any springs depending portions G G, Fig. 4, from the bridge D may be used to bear upon the diaphragm; but in this case the relations of parts, the length of the depending portions, and the distance from the groove C to the diaphragm will have to be accurately adjusted in order that the pressure may be uniform. It is also evident that I may use the bridge without either the precise springs F F or the single modification F of Fig. 3 or the depending solid portions G G, Fig. 4, by tapping springs F F of slightly-diiferent form upon the interior surface of the rim and bent so that their ends may bear upon the diaphragm, as shown in Fig. 5 and as is a well-known arrangement in several varieties of transmit ters.

It will be understood that the exact form of the bridge D is immaterial, the form shown in Figs. 1 and 2 being proper, in which the center part of the bridge is laterally expanded into a circular cap I-I, fitting over the carbon-receptacle I, (preferably a ring of soft fiber,) in which the granulated carbon is held. Connection is made with the granulated carbon by a small screw-post K, (which extends up through the central cut-away portion or well d, as shown,) which screw-post passes through the bridge D and connects with the line-wire L. The structure or form of this carbon-receptacle I and of its connection with the wire is no part of my invention, as various diversities of it are well known. I have made it of a ring of soft fiber resting upon diaphragm E, the carbon being contained therein between the diaphragm E and cap H.

Having described my invention, what I desire to protect by Letters Patent is- 1. In a telephone-transmitter, in combination with a mouthpiece A, a casing B, an upturned part or rim 1), a groove C upon said rim, a slot 0 above said groove, a diaphragm E, resting in said casing, a carbon-receptacle resting upon the diaphragm, and a bridge having ends adapted to slide in groove C,

and means for holding the diaphragm in position.

2. In a telephone-transmitter, in combination with a mouthpiece A, a casing B, an upturned rim 1) thereon, a grooveC upon the inslot in said upturned part to admit one end terior of said rim, a slot cabove said groove, I of said bridge to said groove, a diaphragm a diaphragm E resting in said casing, a carresting in said casing, a carbon-receptacle re- 15 hon-receptacle, a bridge D, and one or more tained between said diaphragm and bridge- 5 springs F, pivoted beneath the bridge and piece, and means to hold said diaphragm in resting against the diaphragm; substantially position; substantially as described.

as described and shown. In witness whereof I hereunto set my hand 3. Inatelephone-transmitter, acasing havthis 2d day of July, 1902. ing an upturned part, adapted to support a FRANK S. TUCKER.

1o diaphragm, a groove upon the upturned part l In presence of of the casing, a bridge-piece having its ex- FRED C. OHAMBERLIN,

tremities adapted to slide in said groove, a HENRY C. THOMSON. 

